/**
 * Created by luwenzheng on 2015/7/16.
 */
function draw(id){
    var canvas = document.getElementById('canvas');
    var context = canvas.getContext('2d');
    context.fillStyle = "#f1f2f3";
    context.fillRect(0,0,400,400);
    context.strokeRect(50,50,180,120);
    context.fillStyle = "green";
}